What's new
Van's Air Force

The definitive Van's Aircraft support community! Buying, building or flying an RV? Join our exclusive family of mentors and enthusiasts!

Surefly SIM, Hot Starts, & Kick back

B

Bcone1381

Well Known Member
Service Difficulty: My Lycoming IO-360 is very difficult to hot start and (rarely) has kickback during start despite taking precautions to avoid this.

My Goal:
  • The SIM delivery of confident Spark every time every cylinder reaches TDC on the start’s compression stroke.
  • Eliminate all kickback risk during hot starts.

Relevant Data:
  • Mechanical FI, Bendix
  • SIM (Surefly Ignition Module) is timed to fire 5 ATDC during start. I deviated from install instructions attempting to avoid kickback during hot starts. It helped 90%.
  • EarthX battery
  • Voltage during start is satisfactory.
    • measured & graphed at the starter during start
    • V has also been found to be satisfactory on the ships Voltage meter.
    • the starter confidently spins the engine verifies this data.
Data I desire to collect:
  • See the ignition system fire trigger timing light during hot starts just to see that power is reaching the spark plug.
    • Can I see the position of the crank during the start anyway?
  • Judge if the EarthX Battery paired with the SIM is a factor.
    • Will the engine start better with a separate EarthX battery powering the SIM?
    • Will the engine start better with a lead acid batter powering the SIM?
  • Measure the Temperature of the case of the SIM.
    • is the starting problems related to SIM temp?
    • Temperature tolerances exist for the SIM….I wonder what they are and how close I am to them during a challenging het start.
  • Data from other SIM/EarthX users.
Kickback Avoidance
  • Kickbacks can cause damage. They will cause wear and tear on starter pinions and ring gears
  • I will continue Kickback avoidance
    • Keep SIM timed 5 ATDC.
    • Limit start attempts to 10 blades per attempt, and two start attempts per minute.
    • Cool down the engine compartment before starting when possible.
 
Bcone1381 said:
  • See the ignition system fire trigger timing light during hot starts just to see that power is reaching the spark plug.
    • Can I see the position of the crank during the start anyway?
Click to expand...
Yes, you can observe WHERE the spark is firing. Set the timing light up on #1. Set crank to TDC. Make a pointer that attaches to the upper case and terminates near the flywheel. Use a sharpie to mark the flywheel with TDC. Move crank to 25* BTDC and make another mark. Now make some other graduated marks in between. Crank away and observe. You can go to ICO to prevent starting, but do not pull plugs out of cylinders. The lack of compression will cause the RPMs to rise above the starting threshold and the sim will think it is in run mode and advance accordingly. If you don't see any of your marks and the light is flashing, the SIM has likely gone wonky and sparking outside of the range you set up. you can put numbered marks all over the flywheel to pin this done. use laquer thinner to remove when done.
 
also out of curiosity, what is the voltage at the SIM connector during cranking? (Not on the EFIS/EIS screen, or gauge on the panel)...

Which part of the engine case is the ground wire connected -- left half (starter side) lug at bottom motor mount, right half (alternator side) lug at bottom motor mount, accessory case (magnetos, fuel pump, prop governor, etc.), or bottom oil sump/induction, or other?
 
Last edited:
lr172 said:
Yes, you can observe WHERE the spark is firing. Set the timing light up on #1. Set crank to TDC. Make a pointer that attaches to the upper case and terminates near the flywheel. Use a sharpie to mark the flywheel with TDC. Move crank to 25* BTDC and make another mark. Now make some other graduated marks in between. Crank away and observe.
Click to expand...
Great Info, I'll try it tomorrow.
Walt said:
Maybe try installing a PC680 just for grins, easy to do and eliminate the EX as a variable.
Click to expand...
I like that idea too.
bjdecker said:
also out of curiosity, what is the voltage at the SIM connector during cranking? (Not on the EFIS/EIS screen, or gauge on the panel)...

Which part of the engine case is the ground wire connected -- left half (starter side) lug at bottom motor mount, right half (alternator side) lug at bottom motor mount, accessory case (magnetos, fuel pump, prop governor, etc.), or bottom oil sump/induction, or other?
Click to expand...
An Oscilloscope was attached to the started in the past and we found voltage to exceed the Surefly stated demands. Today we hooked it up to the Surefly at the SIM Power lead screw. It again exceeded the Surefly standard for this test even with a battery that had many starts on it. Voltage was 10V for a moment when the button was pushed then rose up to 11V during the rest of the crank event.

The engine case has two grounds, one on the left, one on the right. The left ground attached directly to an oil sump attach bolt and the aircrafts ground block on the firewall. The right ground is connected to a different oil sump attach bolt and the lower right motor mount lug at the firewall.

The timing light will be revealing.
 
Ok, here we go.
After more testing this week, more frustration and head scratching. Rechecked everything again! Even modified my starting technique to the point that I could occasionally get the engine to start while hot but it wasn’t a happy start at all, and wasn’t consistent. Still felt there is something wrong with this second SIM.

Yesterday decided to pull the SIM. Went through my Slick mag by pulling the coupling, inspecting the rotor, condenser, coil and changing the points. E-gap set, installed and timed both Slicks. As expected the engine starts easily when cold. What I didn’t expect was that the engine now starts better than it has ever started with an impulse coupled mag while HOT! Starts like it first did years ago with the SIM! Go figure.
My guess is the faster cranking with the EarthX really helps with an impulse coupling. Especially while hot.

So something is definitely not right with this second SureFly. Got a return authorization and will ship it back Monday. Have no idea what testing will reveal because tech support admitted that bench checks don’t involve heating the SIM. In the mean time I’ll concentrate on getting ready for Oshkosh using two Slicks instead of screwing around with the SureFly. At least now I know I’m not losing my mind and have some confidence back.
Will keep you posted on the test results, I’m certain SureFly will make it right. However, not sure if and when I’ll get around to reinstalling the SIM.
Fly safe all! Ray

Copied from previous thread at the request of the OP
 
Last edited:
I had considered trying the PC680 for troubleshooting this, but the cranking was so slow on cold cylinders that the engine would barely turn over. Thats why I switched to EarthX. And again, my first SIM was fine with the lithium battery. Afraid I won’t be able to provide useful data now that I have removed the left SIM. Curious what SureFly will report back with.
 
eatonair said:
I had considered trying the PC680 for troubleshooting this, but the cranking was so slow on cold cylinders that the engine would barely turn over. Thats why I switched to EarthX. And again, my first SIM was fine with the lithium battery. Afraid I won’t be able to provide useful data now that I have removed the left SIM. Curious what SureFly will report back with.
Click to expand...
Following along as I have a SF as well and have considered installing earthx for weight savings at some stage…

If a PC680 won’t spin and start it (assuming it’s not faulty or flat) then there could something else going on here that might be relevant to your troubleshooting.
The vast majority of RVs run PC680s or equivalent with no problems.
 
I am confused by the OP followed by someone answering as if they were the OP but not.

OP, what is your shutdown procedure? What is your hot start procedure? Why do you do it in those manners?
 
Richard Connell said:
Following along as I have a SF as well and have considered installing earthx for weight savings at some stage…

If a PC680 won’t spin and start it (assuming it’s not faulty or flat) then there could something else going on here that might be relevant to your troubleshooting.
The vast majority of RVs run PC680s or equivalent with no problems.
Click to expand...
You are correct. The PC 680 was adequate for starting my IO320 early on. But it seems that now that the engine is broken in (using higher compression pistons) the engine was much harder to turn over while cold. Wasn’t a problem while hot. The EarthX did make a huge difference.
But I’m also using a Skytec starter and not one of the expensive B&C units.
 
eatonair said:
The PC 680 was adequate for starting my IO320 early on. But it seems that now that the engine is broken in (using higher compression pistons) the engine was much harder to turn over while cold. Wasn’t a problem while hot.
Click to expand...
i would argue that the reason for the sluggish performance was an issue with either the battery, starter or wiring. Nothing really changes as the engine breaks in. hot vs cold cranking performance difference kind of sounds like a wiring or starter issue.
 
Bcone1381 said:
Great Info, I'll try it tomorrow.

I like that idea too.

An Oscilloscope was attached to the started in the past and we found voltage to exceed the Surefly stated demands. Today we hooked it up to the Surefly at the SIM Power lead screw. It again exceeded the Surefly standard for this test even with a battery that had many starts on it. Voltage was 10V for a moment when the button was pushed then rose up to 11V during the rest of the crank event.

The engine case has two grounds, one on the left, one on the right. The left ground attached directly to an oil sump attach bolt and the aircrafts ground block on the firewall. The right ground is connected to a different oil sump attach bolt and the lower right motor mount lug at the firewall.

The timing light will be revealing.
Click to expand...

The reason for the O-Scope was to see the quality of the power, not just the quantity. Was it flat DC or did you see "noise" riding on top of it, and if so, what was the Vrms/Vpp and Frequency of the transients?

On engine grounds, the oil sump is probably the worst location for the ground -- even two of them.

Recall how the engine is assembled - two case halves held together/apart by a collection of (ed: greasy) bolts, washers, and nuts with a bead of silk thread and sealant on the case flanges. Similarly for the accessory case and oil pan. Not a low impedance/resistance path.

There are two better locations for engine grounding, and are dependent upon which mode you're in: starting (drawing a lot of current) or running (generating a lot of current).

The best location for starting is at the starter lug or left case half -- this is the lowest impedance path available when the starter is energized -- translates to low voltage drop, more power available to the starter solenoid & motor --- but, not as good after the starter is offline and the current is coming from the alternator.

The best location for running is at the alternator case attachment or right case half -- this is a low impedance path available when the alternator is running -- translates to low voltage drop and more power available to the aircraft buss & systems.

And, while I'm at it -- this is another reason to include the "torque strap" between the starter and alternator lugs -- it provides an electrical connection between the two case halves and current devices.

Edit: removed "passivated" from the description of the case half bolts - LW-25s. They are Cd plated.
 
Last edited:
Hot start: The only thing the SF SIM does differently during the start is to give you more spark energy at TDC. If you have it timed correctly, and the ignition system is good DOWNSTREAM of the SF (even if a sparkplug or harness is new, it can still be bad), your hot start issue is related to fuel, air, or technique.

Kickback: Troubleshooting voltage must be measured at the starter hot electrical post. If it drops below 8-10 Vdc while starting, you run the risk of the SF SIM being forced to operate outside it’s electrical design limit and shutting down. If it shuts down after the coil is charged (near TDC on compression), there is a chance that the charge will be released into the spark plug as the field collapses. Low voltage during the start is usually a poor ground to battery, degraded relay, or a dying battery.

Most of the time the issue is found to be something other than the SF SIM, and it is typically bad ground/power supply, or downstream components. Try using a separate stand alone battery wired directly and only to the SF SIM (hot and ground). If it starts normally it is likely your electrical system. If the issue persists it is likely downstream from the SIM. I think SF will bench test the SIM for a fee and waive the fee if it is faulty. You need to contact their tech support.
 
Last edited:
bjdecker said:
The best location for running is at the alternator case attachment or right case half -- this is a low impedance path available when the alternator is running -- translates to low voltage drop and more power available to the aircraft buss & systems.

And, while I'm at it -- this is another reason to include the "torque strap" between the starter and alternator lugs -- it provides an electrical connection between the two case halves and current devices.
Click to expand...
I guess we underestimate the importance of good grounds. Just because our airplane starts (or sometimes not) doesn’t mean that the current path is optimal. To your point, my ground cable is attached to the right lug near the alternator. Hadn’t really ever considered a torque strap.
 
lr172 said:
i would argue that the reason for the sluggish performance was an issue with either the battery, starter or wiring. Nothing really changes as the engine breaks in. hot vs cold cranking performance difference kind of sounds like a wiring or starter issue.
Click to expand...
I suppose you have a point. The SkyTec starter isn’t the best out there. I’m sure the EarthX is making it look better than it really is. Brian has some good points about grounding as well. But the cranking is better than it has ever been. So today I wanted to know exactly what the cranking RPMs are while hot. (Just to eliminate that possibility)

Started the airplane without issue (two mags, no SIM). Flew around the airport for a few laps. Returned to the hangar and shut down. Restarted multiple times just to be sure it wasn’t my imagination.
With mags off, measured cranking speed using laser tachometer at 226-250 rpm while hot. As you have suggested, no where near the 400 rpm threshold for the SIM. One more box I can check off.
Perhaps Brooks can verify his cranking speed just to eliminate that.
 
bjdecker said:
On engine grounds, the oil sump is probably the worst location for the ground -- even two of them.

Recall how the engine is assembled - two case halves held together/apart by a collection of (ed: greasy) passivated bolts, washers, and nuts with a bead of silk thread and sealant on the case flanges. Similarly for the accessory case and oil pan. Not a low impedance/resistance path.
Click to expand...

Lycoming case fasteners are cad plated steel and NOT passivated bolts. Passivation is a process used on stainless fasteners for removal free iron to prevent them from rusting.

With that said, all case and sump parts are held together with through fasteners that provide robust conduction paths across the joints so silk threads, gaskets, etc. should have minimal impact on conductivity of the ground path to the starter. As long as the ground strap is making good metal to metal contact (i.e. no paint) to the case or sump, there will be a solid conduction path to the starter.

Skylor
 
RNB said:
I am confused by the OP followed by someone answering as if they were the OP but not.

OP, what is your shutdown procedure? What is your hot start procedure? Why do you do it in those manners?
Click to expand...
SHutdown is by placing the mixture in ICO. Hot start procedure....its never hot started well. I let it cool down by opening the cowl doors (Bearhawk Patrol). To avoid kickback I do short start attempts. kickbacks happen on long starts.

I'm not going to go thru my hot start procedure becuase its never hot started well, and I have had kickback issues with long start attempts. Short start attempts relieve the kickback problem to a very large degree. I understand where my mixture is (Lean or rich) and try have it sweep thru a satisfactory state during a start attempt. I only prime if I am very confident its lean....

Eatonair and I have the same issue...that might explain why is seems confusing. I started this thread due to another thread that this issue came up so it could have its own title and focus.
 
bjdecker said:
The reason for the O-Scope was to see the quality of the power, not just the quantity. Was it flat DC or did you see "noise" riding on top of it, and if so, what was the Vrms/Vpp and Frequency of the transients?

On engine grounds, the oil sump is probably the worst location for the ground -- even two of them.

Recall how the engine is assembled - two case halves held together/apart by a collection of (ed: greasy) passivated bolts, washers, and nuts with a bead of silk thread and sealant on the case flanges. Similarly for the accessory case and oil pan. Not a low impedance/resistance path.

There are two better locations for engine grounding, and are dependent upon which mode you're in: starting (drawing a lot of current) or running (generating a lot of current).

The best location for starting is at the starter lug or left case half -- this is the lowest impedance path available when the starter is energized -- translates to low voltage drop, more power available to the starter solenoid & motor --- but, not as good after the starter is offline and the current is coming from the alternator.

The best location for running is at the alternator case attachment or right case half -- this is a low impedance path available when the alternator is running -- translates to low voltage drop and more power available to the aircraft buss & systems.

And, while I'm at it -- this is another reason to include the "torque strap" between the starter and alternator lugs -- it provides an electrical connection between the two case halves and current devices.
Click to expand...
The scope showed normal variation due to the stress of the starter pushing a piston over a compression stroke. It was not noisey. The other data is unknown to me. My best friend at the airport has the scope...he has automotive manufacturing R&D backgournd with Ford and Toyota. Freq of transmits was multiple per second though. way more than 6/sec. 25? I dont know.

I've noted your ground concerns and have added it to the list. I like that thinking.
 
pecanflyboy said:
Hot start: The only thing the SF SIM does differently during the start is to give you more spark energy at TDC. If you have it timed correctly, and the ignition system is good DOWNSTREAM of the SF (even if a sparkplug or harness is new, it can still be bad), your hot start issue is related to fuel, air, or technique.

Kickback: Troubleshooting voltage must be measured at the starter hot electrical post. If it drops below 8-10 Vdc while starting, you run the risk of the SF SIM being forced to operate outside it’s electrical design limit and shutting down. If it shuts down after the coil is charged (near TDC on compression), there is a chance that the charge will be released into the spark plug as the field collapses. Low voltage during the start is usually a poor ground to battery, degraded relay, or a dying battery.

Most of the time the issue is found to be something other than the SF SIM, and it is typically bad ground/power supply, or downstream components. Try using a separate stand alone battery wired directly and only to the SF SIM (hot and ground). If it starts normally it is likely your electrical system. If the issue persists it is likely downstream from the SIM. I think SF will bench test the SIM for a fee and waive the fee if it is faulty. You need to contact their tech support.
Click to expand...
I want confidence that I have a spark at TDC during start. I wanted to measure if timing drifts off TDC during a hot start using a timing light today. Things did not work out. EatonAir had the same issue I am having. Other users have had kickback on starts with SIM. I backed off the timing during start to 5 ATDC to battle kickback and hot start issues. So I am now "off campus" Am I timed correctly? I just want to know when that SIM fires the spark when its case is 175F. That is the question.

Yeah, Hot Starts with Bendix....its a fuel, , mixture, technique fiasco. Did it fail to start due to rich, or lean? Well, now we know Eaton Air's starts just fine with the SIM swapped out for a mag. So I am now back to questioning the quality of the spark event during start.

The V drop at the starter hot post was checked last year when this first arose...using that same oscilliscope. The Voltage met Surefly's standard. It was Like 11V.

i will do a hot start attempt with a stand alone battery - That is a good idea. I will also run a dedicate ground from the SIM to the ground bus. We will also remove the P-lead to eliminate a source. But it runs just fine cold, and hot after starting. Its a really nice efficient product outside hot starts.

My gut tells me the Surefly has a heat related spark timing issue when its hot. just my gut. Probably wrong. I hope this is all my installation issue. We'll get it figured out.
 
Last edited:
Let me throw in a data point. I have a surefly on my Mooney with an IO-360. We had a prop strike and had to the engine inspection. As part of it, we had to send the surefly in for its sudden stoppage inspection. When we got it back it would not hot start. It started great cold, but once it got hot it would NOT start. Sometimes we would even have trouble getting it to start just from the heat of the day in the afternoons. We went rounds with surefly support. We hooked up external batteries to isolate it from ships power, completely disconnected the P-leads, etc. all with no luck. We finally got surefly to agree to swap it under warranty and voila! It started hot first try and every try since then. I still don't know the actual issue, but I can say that there is a fault with sureflys that will make it stop working when hot.
 
Thanks bob865. This is very helpful information. I too feel like I just got a defective rebuilt unit. Shipping mine back tomorrow. Hopefully SF can get it figured out.
Bcone1381 said:
bob865 said:
Let me throw in a data point. I have a surefly on my Mooney with an IO-360. We had a prop strike and had to the engine inspection. As part of it, we had to send the surefly in for its sudden stoppage inspection. When we got it back it would not hot start. It started great cold, but once it got hot it would NOT start. Sometimes we would even have trouble getting it to start just from the heat of the day in the afternoons. We went rounds with surefly support. We hooked up external batteries to isolate it from ships power, completely disconnected the P-leads, etc. all with no luck. We finally got surefly to agree to swap it under warranty and voila! It started hot first try and every try since then. I still don't know the actual issue, but I can say that there is a fault with sureflys that will make it stop working when hot.
Click to expand...
That is exactly what is happening to my replacement SIM. (The first had a loose/failing coil pack at 209 hrs.)
Click to expand...
Bcone1381 said:
I want confidence that I have a spark at TDC during start. I wanted to measure if timing drifts off TDC during a hot start using a timing light today. Things did not work out. EatonAir had the same issue I am having. Other have had kickback on starts with SIM. I backed off the timing during start to 5 ATDC to battle kickback and hot start issues. So I am now "off campus" Am I timed correctly? I just want to know when that SIM fires the spark when its case is 175F. That is the question.

Yeah, Hot Starts with Bendix....its a fuel, , mixture, technique fiasco. Did it fail to start due to rich, or lean? Well, now we know Eaton Air's starts just fine with the SIM swapped out for a mag. So I am now back to questioning the quality of the spark event during start.

The V drop at the starter hot post was checked last year when this first arose...using that same oscilliscope. The Voltage met Surefly's standard. It was Like 11V.

i will do a hot start attempt with a stand alone battery - That is a good idea. I will also run a dedicate ground from the SIM to the ground bus. We will also remove the P-lead to eliminate a source. But it runs just fine cold, and hot after starting. Its a really nice efficient product outside hot starts.

My gut tells me the Surefly has a heat related spark timing issue when its hot. just my gut. Probably wrong. I hope this is all my installation issue. We'll get it figured
Click to expand...
 
eatonair said:
I suppose you have a point. The SkyTec starter isn’t the best out there. I’m sure the EarthX is making it look better than it really is. Brian has some good points about grounding as well. But the cranking is better than it has ever been. So today I wanted to know exactly what the cranking RPMs are while hot. (Just to eliminate that possibility)

Started the airplane without issue (two mags, no SIM). Flew around the airport for a few laps. Returned to the hangar and shut down. Restarted multiple times just to be sure it wasn’t my imagination.
With mags off, measured cranking speed using laser tachometer at 226-250 rpm while hot. As you have suggested, no where near the 400 rpm threshold for the SIM. One more box I can check off.
Perhaps Brooks can verify his cranking speed just to eliminate that.
Click to expand...
I was more suggesting that the problem could have existed before the earth x replacement and got resolved during that effort, making you think all of the improvement was from the new battery. The 680 could also have been degraded and was performing below typical.
 
Bcone1381 said:
.

My gut tells me the Surefly has a heat related spark timing issue when its hot. just my gut. Probably wrong. I hope this is all my installation issue. We'll get it figured out.
Click to expand...
based upon all you and eaton have posted, i feel the same. This stuff definitely happens in some cases when microprocessor based boards get real hot.
 
lr172 said:
based upon all you and eaton have posted, i feel the same. This stuff definitely happens in some cases when microprocessor based boards get real hot.
Click to expand...
Which is why I’ve never been a fan of pmag, bolting a computer to an engine just never seemed like a great idea. Having been an electronics guy for a few decades it just seems like a bad idea. When the primary objective is easy installation / interchangeability then compromises must be made.
 
Last edited:
skylor said:
Lycoming case fasteners are cad plated steel and NOT passivated bolts. Passivation is a process used on stainless fasteners for removal free iron to prevent them from rusting.

With that said, all case and sump parts are held together with through fasteners that provide robust conduction paths across the joints so silk threads, gaskets, etc. should have minimal impact on conductivity of the ground path to the starter. As long as the ground strap is making good metal to metal contact (i.e. no paint) to the case or sump, there will be a solid conduction path to the starter.

Skylor
Click to expand...

You win - they're not passivated. The LW-25s are Cd plated. I updated my post accordingly.
 
Just as another data point, I have experienced the same problem. Very difficult if not impossible to start when hot and occasional kick backs when cranking. New RV14 with IO-390 from Lycoming with dual Surefly (Lycoming badged) mags, EarthX 900 battery. Backup battery for the second mag as per Lycoming instructions. The setup is exactly as per the instructions and I double checked the timing. I have had some success using various hot starting techniques heard around the airport- ask five people you’ll get six different techniques. Even talked to Vans Tech Support. I would be interested to know if anyone finds a smoking gun on the hot starting issue.
 
DaneP said:
Just as another data point, I have experienced the same problem. Very difficult if not impossible to start when hot and occasional kick backs when cranking.
Click to expand...
Difficulty with hot starts can be a lot of things, including ignition, but kickbacks are most often the result of too much advance. Every once in a while the avg guy gets a prop stoppage / reversal, but fairly common kickbacks are a sign that too much advance is being applied during start.

It would seem there is possibly some weakness in the system with heat that appears in a small number of cases. Will be interesting to see how this gets resolved. i can't imagine it is wide spread or we would have heard a lot more complaints.
 
Another data point. On my new RV-10 with an IO-540 and dual Lycoming EIS (rebadged Surefly units) I have had no issue with hot starts and I have had some toasty starts after fuel stops. I have dual EarthX 900s. Big difference I see is 6 vs 4 cylinders, I wonder if there is something different in the design between the two.
 
Walt said:
Which is why I’ve never been a fan of pmag, bolting a computer to an engine just never seemed like a great idea. Having been an electronics guy for a few decades it just seems like a bad idea. When the primary objective is easy installation / interchangeability then compromises must be made.
Click to expand...
To me it is somewhat counterintuitive. I do love the technology, especially when you have the ability to pull over when something goes wrong. But with airplanes the rule is keep it simple, so why are they getting so complicated. I work on brand new jets every day and the number of computer controlled boxes, gadgets and widgets we replace is mind boggling. I could go on for hours about the electronic issues we see.
 
DaneP said:
Just as another data point, I have experienced the same problem. Very difficult if not impossible to start when hot and occasional kick backs when cranking. New RV14 with IO-390 from Lycoming with dual Surefly (Lycoming badged) mags, EarthX 900 battery. Backup battery for the second mag as per Lycoming instructions. The setup is exactly as per the instructions and I double checked the timing. I have had some success using various hot starting techniques heard around the airport- ask five people you’ll get six different techniques. Even talked to Vans Tech Support. I would be interested to know if anyone finds a smoking gun on the hot starting issue.
Click to expand...
So the more we talk about this issue, more pilots are coming forward with similar issues which is a good thing. I don’t mean to suggest that they are all related to SureFly SIMs as some are probably just vapor lock or flooding issues. And even on a good day, a lycoming can be ornery to say the least. I think it’s important that we differentiate between engines that are tough to start and those that cannot start.

In my case I know without a doubt that something had changed. Something was very different and very wrong. The Slick mag proved that. I truly hope that SureFly can figure it out and is willing to share the results. As we all are.

Unfortunately for some of you, like Brooks and yourself, you may not have a baseline to compare with. Meaning this is the way the airplane has always been been, therefore you may have assumed it was starting technique. When in fact it has been something more insidious the whole time. Just playing devils advocate. 😉
 
eatonair said:
So the more we talk about this issue, more pilots are coming forward with similar issues which is a good thing. I don’t mean to suggest that they are all related to SureFly SIMs as some are probably just vapor lock or flooding issues. And even on a good day, a lycoming can be ornery to say the least. I think it’s important that we differentiate between engines that are tough to start and those that cannot start.

In my case I know without a doubt that something had changed. Something was very different and very wrong. The Slick mag proved that. I truly hope that SureFly can figure it out and is willing to share the results. As we all are.

Unfortunately for some of you, like Brooks and yourself, you may not have a baseline to compare with. Meaning this is the way the airplane has always been been, therefore you may have assumed it was starting technique. When in fact it has been something more insidious the whole time. Just playing devils advocate. 😉
Click to expand...
eatonair said:
So the more we talk about this issue, more pilots are coming forward with similar issues which is a good thing. I don’t mean to suggest that they are all related to SureFly SIMs as some are probably just vapor lock or flooding issues. And even on a good day, a lycoming can be ornery to say the least. I think it’s important that we differentiate between engines that are tough to start and those that cannot start.

In my case I know without a doubt that something had changed. Something was very different and very wrong. The Slick mag proved that. I truly hope that SureFly can figure it out and is willing to share the results. As we all are.

Unfortunately for some of you, like Brooks and yourself, you may not have a baseline to compare with. Meaning this is the way the airplane has always been been, therefore you may have assumed it was starting technique. When in fact it has been something more insidious the whole time. Just playing devils advocate. 😉
Click to expand...

You’ ve been registered on this forum for quite a while, seems like 75% of your posts are on this SIM stuff???

Folks are talking about hot start problems and yet fail to describe their start methods, maybe not even describing their shut downs to prepare for the hot start as expected.
 
RNB said:
You’ ve been registered on this forum for quite a while, seems like 75% of your posts are on this SIM stuff???

Folks are talking about hot start problems and yet fail to describe their start methods, maybe not even describing their shut downs to prepare for the hot start as expected.
Click to expand...

Admittedly I haven’t been keeping up VAF for some time. When I had the first SIM problem, I figured it would be well covered here already. It wasn’t, so I did. The lack of information on this subject bothers me and it’s reassuring to know that others are experiencing the very same.

As for starting methods. Cold, full rich prime 5 sec with WOT. Crank with 1/4 throttle and idle cutoff. SIM would fire in two blades. Add fuel and right mag. Never an issue.
Hot starting, (with the SIM installed) crank 1/2-3/4 throttle, no fuel added. Also depends on how long the engine had been percolating. Will usually fire within 4 blades. If first attempt is unsuccessful, 3 sec prime then WOT until it fires.
Probably not the way you do it but it works for me. Please share your technique.
 
eatonair said:
Admittedly I haven’t been keeping up VAF for some time. When I had the first SIM problem, I figured it would be well covered here already. It wasn’t, so I did. The lack of information on this subject bothers me and it’s reassuring to know that others are experiencing the very same.

As for starting methods. Cold, full rich prime 5 sec with WOT. Crank with 1/4 throttle and idle cutoff. SIM would fire in two blades. Add fuel and right mag. Never an issue.
Hot starting, (with the SIM installed) crank 1/2-3/4 throttle, no fuel added. Also depends on how long the engine had been percolating. Will usually fire within 4 blades. If first attempt is unsuccessful, 3 sec prime then WOT until it fires.
Probably not the way you do it but it works for me. Please share your technique.
Click to expand...

I really don't have issues that worry me, but if I did, I'd refer back to these instructions. Note that the hot start process begins with the shut down process:

Engine shut downs and Hot starts (RV10 IO540)

I'm building out or personalizing my checklists and want some help to internalize and understand engine shut downs and hot starts. I'm coming from C172 where idle power and pull mixture was the shut down and the plane never had a tough time starting back up. I'm now in a bigger better plane...
vansairforce.net
 
RNB said:
You’ ve been registered on this forum for quite a while, seems like 75% of your posts are on this SIM stuff???

Folks are talking about hot start problems and yet fail to describe their start methods, maybe not even describing their shut downs to prepare for the hot start as expected.
Click to expand...
If the issue is kickback, then its a spark timing issue. I have connected the two together and I am not the only one who has both going on. So for now the issue is focused on the timing of the spark during hotstart.
 
Last edited:
Kaos2800 said:
What’s your hot start procedure?
Click to expand...
The first start is fule pump off, mixture lean, throttle at at 1100 rpm from shutdown. If its a no start, I evaluate if I think the mixture is rich or lean. If in doubt assume its rich and then do sweep on the next start attempt to increase confidence of the mixture situation. Then I prime and do mixture sweeps while starting. No best practice can be established until confident success at hot starting is met, and this has never been achieved.
 
Last edited:
I'm not very experienced but, my sense of logic is that if an engine starts appropriately when cold, the timing of the magnetos/SIM/whatever is good and normal. Is there some part of timing adjustment that happens in a Surefly that advances or retards timing when hot?

Some of the posters with these problems seem to operate from a point of view that limits what they are willing to examine as potential issues. When I have issues, I try to lay it all out there because the goal is to solve the problem, not to be right/save face/preserve ego. IF one operates with problem hot starts but fails to question there own knowledge or share all available info, then the proper solution might be out of reach. In short, I think pilot owners need to examine beliefs and conceptions when facing problems.

For me, the cold start being normal is key! Then one has to look at what is different. If the SIM or other modern magneto replacement does not change timing when on the ground, other factors need to be looked at. Key of which is the word used "Hot".

So, are all the factors that look at heat examined as they impact the combustion cycle? I don't know what all they are, but assume too much fuel is really a big one. That is why I want to have awareness of shut down processes along with start up processes. The Surefly offers "hotter" spark, more energy, this needs be understood.

Spark plugs? What spark plugs are in use and how do you know they are the right ones? The wrong plug selection with regards to heat ranges can lead to detonation (Lycoming engine school). The wrong reach of the spark plug in the port can cause hot spots and preignition. Are the spark plugs properly seated to dissipate heat? Are the spark plugs gapped per Surefly, ie wider gap? Aviation spark plugs – gapped .022 to .035 (surefly site).

Surefly site says the sparks are retarded at startup: Starting: Retards spark to TDC w/full spark energy

Has anyone taken an impacted airplane to Surefly or a Surefly installer? I'd aim for a high volume installer that really knows the product. Perhaps fly with another pilot that has a surefly and see how they do things successfully.

I'd also consider a suction holder for a phone that focuses on the avionics during shut down and start up. Talk thru what you are doing. And if you have a light speed Zulu I think their app even records for you.

Another thing, who installed the Surefly? Have you read thru the manuals to make sure it was done correctly?

pv=nrt
 
So when we got our -8 we followed the advice that the previous owner provided, that was the same as another 8 owner provided to us and I of course provided here in another post.

It seemed to work…except when it didn’t. The worst and most difficult was on quick turns. Engine shut down, taking on fuel or a passenger swap, and a restart. I dreaded those. Particularly during formation clinics.

Now, to add. I had read posts on here. I looked in the Lycoming manual we have, I looked all over. I saw the friend with another fuel injected 360 but different mags having trouble.

After some pretty hard starts another teammate who fly’s a carbureted engine said why don’t you read:

———
Starting Woes, Part 2
What to do when it still won’t start

BY VIC SYRACUSE
———

So I did, and in reading it I thought, damn if that’s not the exact same procedure as a fuel injected Piper Arrow! Which I have hundreds of hours in.

I’ve since changed to what I already knew. Since then I’ve had. No hard starts, No chugging, No black smoke, No anxiety.

——

I know you know this, but I have to say it as I’ve seen a few pilots do this. always shut the engine down with throttle closed, and mixture to idle cut off. Do not use the mag switch, only once the prop stops moving do you turn the mags off.

The hot start.

Prop forward
Throttle closed, then 1/4 inch open
Mixture Idle cutoff
No fuel pump/priming you do this and your hosed just like turning the mags off.

Engage the starter, only when the engine catches do you slowly add in mixture. This is the art part. If you don’t add it quickly enough it will die and potentially lose its prime. Then starting can become slightly harder. Add it too fast and you can flood it. Most people that I’ve taught this to, they figure out that speed within just a few hot starts.

And when adding the mixture in you’re only really need to add it basically ground lean. You aren’t sweeping the mixture up and down, back and forth. Just a smooth steady movement from idle cutoff to about half rich. It’s fine if you go for Rich too you just don’t wanna go too fast.

So far in my experience, since switching over to the method that I already knew. The engine only doesn’t run when I screw it up and typically it’s from adding fuel too quickly. And in the cases where it does die, I’ve been able to turn around and do it again and it works that second time.

———

The method that I was originally taught that generally works, but has a lot more theatrics is for when it’s been flooded. You know someone turned off the mag switch before the engine stopped so there’s extra fuel in the cylinder or I did something stupid and hit the fuel pump forgetting that the engine is hot and I flooded it.

In that case, it’s:

throttle wide open
mixture idle cut off
No fuel pump

Hit the starter as the engine catches you’re pulling back the throttle while feeding in the mixture

———

Just my two cents it’s at least worth a try and I hope you are able to find a resolution because I know how it feels and it’s not fun. In our plane should be enjoyable.
 
Last edited:
Hot Start issues are often fuel related. With that being said, I do not want this thread to turn into a fuel mixture thread. Kickback is part of this issue. Kickback is a pre-ignition issue. It is an indicator that timing may not be at TDC. Pre-ignition might be from a hot spot, or from a spark happening before TDC.
 
Success!! The SIM works as it should when it is powered by its own dedicated power supply. Below is the long story.

I talked yesterday with Surefly product support: Jordan and Matt had me first double check the timing of the SIM. Their view is that timing TDC with the flywheel marks and the starter pointer is unsat. They have data that says Errors in fly wheel markings exists. The Surely approved method is now timing TDC using a dial indicator. My findings on my flywheel is marking are accurate. So I had No Joy.

Timing Light: Real quick. I ran out of time yesterday to shoot the timing on a hot engine.

But Matt and Jordan directed me to isolate the SIM from my aircraft electircal system. The SIM Isolation Procedure is here.

This is the short version of the procedure.
1) Pull the SIM fuse.
2) Disconnect the P-lead. On-Off switch does not function.
3) Connect a wire from the SIM power source to the + terminal of a second battery.
4) Connect a ground wire from the SIM to the - side of the second battery. (SIM is now hot. on-off switch does not control ignition..its just on and dangerous)

I needed to test the SIM hot, not cold. For safety reasons I set up the R. SIM and went flying to get it hot.

Peak Cowl heat happens 10-15 minutes after shutdown. So I shutdown, marked my watch, pulled the R SIM fuse, and installed the two wires onto the second battery.

After 13 minutes I tried to start the motor on just the R SIM isolated to the extra battery.

Success! It almost started on the first attempt. I started on the second start attempt. Wow! I thought I was lucky, or the engine wasn't really as hot as it was yesterday. I measured the base of the R SIM and it was 180F. 2 degrees hotter than before. So I tried a second start sequence. Success again. No problem starting. I've never had it hot start like this. It exceeded my expectations.

But wait...what was it the P-lead? Was it the Ground? or was it the Voltage supply? We'll see. But now we know, it was not a problem with fuel mixture. For 18 months I thought it was fuel mixture for hot start issues and just puzzled at the kickback issue. Eatonair has shared his story about how a swap to a Mag fixed his SIM hot start issue and it prompted me to investigate further.

I venture to guess, with 85% confidence, that I will be installing a backup battery to keep Voltage up at the SIM's during start. Not sure what I will do from here, but I have good data to guide the route.
 
Last edited:
Bcone1381 said:
Success!! The SIM works as it should when it is powered by its own dedicated power supply...
Click to expand...
Curious if your original setup had the SIM power connected directly to the battery (using the supplied fuse holder) or if it was powered through a switch. And did you just swap the power wire over to the second battery, or is it a new power wire now?
 
Bcone1381 said:
Success!! The SIM works as it should when it is powered by its own dedicated power supply. Below is the long story.
<snip>
I venture to guess, with 85% confidence, that I will be installing a backup battery to keep Voltage up at the SIM's during start. Not sure what I will do from here, but I have good data to guide the route.
Click to expand...
Interesting, but glad you were able to determine there is no fault with the SureFly.

As a datapoint, my SureFly is powered directly off the battery and has never suffered from voltage drop during start.
 
Bcone1381 said:
Success!! The SIM works as it should when it is powered by its own dedicated power supply. Below is the long story.

I talked yesterday with Surefly product support: Jordan and Matt had me first double check the timing of the SIM. Their view is that timing TDC with the flywheel marks and the starter pointer is unsat. They have data that says Errors in fly wheel markings exists. The Surely approved method is now timing TDC using a dial indicator. My findings on my flywheel is marking are accurate. So I had No Joy.

Timing Light: Real quick. I ran out of time yesterday to shoot the timing on a hot engine.

But Matt and Jordan directed me to isolate the SIM from my aircraft electircal system. The SIM Isolation Procedure is here.

This is the short version of the procedure.
1) Pull the SIM fuse.
2) Disconnect the P-lead. On-Off switch does not function.
3) Connect a wire from the SIM power source to the + terminal of a second battery.
4) Connect a ground wire from the SIM to the - side of the second battery. (SIM is now hot. on-off switch does not control ignition..its just on and dangerous)

I needed to test the SIM hot, not cold. For safety reasons I set up the R. SIM and went flying to get it hot.

Peak Cowl heat happens 10-15 minutes after shutdown. So I shutdown, marked my watch, pulled the R SIM fuse, and installed the two wires onto the second battery.

After 13 minutes I tried to start the motor on just the R SIM isolated to the extra battery.

Success! It almost started on the first attempt. I started on the second start attempt. Wow! I thought I was lucky, or the engine wasn't really as hot as it was yesterday. I measured the base of the R SIM and it was 180F. 2 degrees hotter than before. So I tried a second start sequence. Success again. No problem starting. I've never had it hot start like this. It exceeded my expectations.

But wait...what was it the P-lead? Was it the Ground? or was it the Voltage supply? We'll see. But now we know, it was not a problem with fuel mixture. For 18 months I thought it was fuel mixture for hot start issues and just puzzled at the kickback issue. Eatonair has shared his story about how a swap to a Mag fixed his SIM hot start issue and it prompted me to investigate further.

I venture to guess, with 85% confidence, that I will be installing a backup battery to keep Voltage up at the SIM's during start. Not sure what I will do from here, but I have good data to guide the route.
Click to expand...
glad to hear. While there could certainly be wiring issues, if the engine is cranking with good authority when hot, there is a good chance you are above the 10V minimum spicified by SF. The fact that it fails on main batt, but works off a separate batt and does fine cold butr not hot, would seem to imply there could be an issue inside the simm where excessive internal resistrance is created when the unit is hot. Not sure this test means there is no simm issue here. The increased resistance could create a scenario where 11V is inadequate, but 13V is fine, which is kind of what your test did. I would keep pressure on the SF folks.
 
Last edited:
Bcone1381 said:
But wait...what was it the P-lead? Was it the Ground? or was it the Voltage supply?
Click to expand...

Bcone1381 said:
I venture to guess, with 85% confidence, that I will be installing a backup battery to keep Voltage up at the SIM's during start. Not sure what I will do from here, but I have good data to guide the route.
Click to expand...
Installation instructions are a good thing. Is the SureFly SIM powered directly from the battery? If not, every circuit breaker and/or switch can become a point of failure for your ignition. The only time you want to use a backup battery is with your second SIM. The first should go directly to the battery. Don't go down a rabbit hole with speculation, call SF tech support. The most tested piece of the puzzle is the SF SIM. Be open to looking elsewhere.

That said, I'm a little concerned that you still don't understand you have a problem with your aircraft. By using a separate battery for SF SIM power, you confirmed that your aircraft has an electrical issue (after a lot of finger pointing at the SureFly). Installing a Band-Aid backup battery is not the answer, nor is it part of the installation unless it is the second SIM.

P-Lead: It is a simple ground-open circuit. The ground tells the unit to turn off, the open to turn on. Check the wire and switch.
Ground: Check all terminals for proper crimps and corrosion.
Battery: Even though it spins the prop, doesn't mean it is good. Try a new one. If you are powering the SF SIM through a circuit breaker, switch, bus bar, or relay fix this immediately! Wire it directly to the aircraft battery.

I had a similar issue when I first installed the SureFly generation 1, many years ago. I cleaned the starter pad as that is the ground for the starter. Checked and cleaned all the terminals. Beefed up the engine to firewall ground. This not only fixed the SureFly issue but suddenly my starter worked as it should!
 
lr172 said:
glad to hear. While there could certainly be wiring issues, if the engine is cranking with good authority when hot, there is a good chance you are above the 10V minimum spicified by SF. The fact that it fails on main batt, but works off a separate batt and does fine cold butr not hot, would seem to imply there could be an issue inside the simm where excessive internal resistrance is created when the unit is hot. Not sure this test means there is no simm issue here. The increased resistance could create a scenario where 11V is inadequate, but 13V is fine, which is kind of what your test did. I would keep pressure on the SF folks.
Click to expand...
I would suspect that the likelihood of lower battery voltage would be starting the engine cold not when the engine is hot just after the alternator has had a chance to recharge the battery. Usually in my experience a hot engine take less power to crank over than a cold one. I would still suspect a problem with the SF and or wiring issues.
 
You must log in or register to reply here.
Back
Top